1. Technical Field
The present invention relates to solid-state storage subsystems. More specifically, the present invention relates to multiple signal interfaces and bus structures for a single solid-state storage subsystem.
2. Description of the Related Art
Solid-state storage subsystems transfer data with host computer systems by means of a wide variety of signal interfaces. A signal interface is typically selected for a particular application based on design constraints facing that application. Design constraints may typically include practical environmental and development matters: the distance separating the storage subsystem and a host system interfaced with the storage subsystem; power consumption; rates of data transfer; design time available on a project; and the cost to implement the bus structure for that signal interface. Because constraints are often similar for similar applications, a particular signal interface may become standard for a given application. For example: the IEEE-1394 signal interface and corresponding bus structure are commonly used for video applications because of the high data rates involved; the USB signal interface and bus structure are commonly used for small data storage applications; and the IDE and SATA signal interfaces and bus structures are used for large data storage and booting applications.
While a particular application may typically call for a particular signal interface, it need not always use that same signal interface. For example, when design time and budget are minimal, an off-the-shelf solution may be used. If a Single Board Computer is used the designer may be limited to using an on-board IDE controller and PATA signal interface regardless of the application because of these time and budget considerations. In this example only a limited number of storage subsystems, those compatible with an PATA signal interface and IDE bus structure, will be compatible with the application host system.
More general industry trends may also cause different signal interfaces and bus structures to be used for similar applications. For example, the IEEE-1394 signal interface and bus structure are commonly used for video applications as stated above. However, the USB 2.0 signal interface has increasingly been used for these types of applications. A storage subsystem relying entirely on either the IEEE-1394 signal interface or USB 2.0 signal interface will therefore not be compatible with a large percentage of systems in the field for which it is designed.
Other host computing systems operate multiple applications, and may face different constraints with each application. The host computing system may therefore have a different signal interface and bus structure for each application, and may therefore require numerous storage subsystems for a single host system.